DESCRIPTION: (Applicant's Abstract) Age-related macular degeneration is the most common cause of blindness among elderly people in the U.S. The etiology of this condition is unknown, and treatment options are limited. There is evidence that a familial predisposition exists, but the exact role of genetics in the disorder is unknown. In addition, there is increasing evidence which suggests that environmental and biological factors are related to expression of the disease. We hypothesize that affected individuals have an underlying genetic susceptibility to development of the disorder. The purpose of this study is to determine the genetic susceptibility to development of age-related macular degeneration. Singleton families will be recruited for candidate gene analysis and multiplex families will be enrolled for general genomic screening. In addition, detailed biochemical and risk factor data will be collected on affected and unaffected subjects in the study. The information derived from this study will provide valuable new insight into the pathophysiology of this age-related disease.